Addiction vulnerability genes include those that are likely to harbor allelic variants that contribute to human individual differences in vulnerability to addictions. During this year, we identified more than 80 such genes based on the covergences between nominally-positive data derived from five separate abuser/control comparisons. We added to evidence supporting roles for many of these genes with additional data from several comparisons between nicotine depdendent and control samples. We added additional support from comparisons between smokers who were successful vs unsuccessful in quitting in clinical trials. Genes identified in this fashion include a disproportionate number of genes whose products are involved in cell adhesion molecule actions. During this year we identified the frequent functional variations at the loci that contain these genes, including splicing variants, missense variants, veriations in 3 and 5 untranslated regions, variations in 5 flanking sequences and variaitons in natural antisense tanscripts. A number of these variations appear to be closely associaiated with addiction vulnerability haplotypes. During the year we reported results from studies of other addiction vulnerability genes, including a transporter gene.